During our presently funded two year feasibility study, a prototype dot-matrix printing system using cerium oxide ribbons was used to fabricate patient-specific radiographic compensation filters. Phantom results suggest that these filters result in improved visualization of structures in areas which normally are poorly penetrated. There is a proposal for a three-year program with the following specific aims: 1. Development of a clinically practical selective exposure chest radiography technique based on our compensation filters; 2. Clinical comparison of compensated and conventional chest radiography; 3. Theoretical and experimental feasibility studies of multi-energy compensated chest radiography techniques. The first specific aim includes several hardware and software developments required for adequate printing speed and physical corrections to the test shot data. In addition, phantom optimization studies will be performed. The clinical evaluation will be in two parts: (1) quantitative comparison of observer performance for detection of nodules in patients referred for chest CT and (2) subjective evaluation of anatomical features in compensated and uncompensated chest radiographs. The multi-energy feasibility study will involve computer simulations and phantom experiments designed to investigate potential techniques which might combine the advantages of spatially selective exposure the tissue-specific imaging.